pratt



No. 627,350, Patented June 20, I899. F. A. PRATT.

DROP HAMMER OPERATING MECHANISM.

(Application filed Oct. 28, 1898.)

(n6 Model.) 2 Sheets-Sheet No. 627,350. Patented June 20, I899. F. A. PRATT.

DROP HAMMER OPERATING MECHANISM.

(Application filed Oct. 28, 1898.)

2 Sheets8heet 2.

We Model.)

Illlll llllll '4 I||||| Illl lmlm llllllll FRANCIS A. PRATT, on HARTFORD, CONNECTICUT.

DROP- HAMMER- QP'ERATING MECHANISM.

srnoirxcnmion forming part of Letters Patent No. 627,350, dated June 20, 1899.

Application filed October 28, 1898. $erial No. 694,809. (No model.)

To all whom it may concern:

specification.

This invention relates to the mechanism which is employed for operating the hammerboard gripping and releasing rolls of a drophammer.

The object of the invention is to provide a simple, durable, and finely-adjustable mechanism which will operate the gripping and releasing rolls surely, smoothly, and without shock and cause the hammer-head to be antomatically lifted and dropped rapidly without loud noise, thus increasing the efficiency of the hammer and minimizing the objectionable features.

The drop-hammer illustrated as embodying the invention has a bed with standards forming a guideway, a hammer-head movable up and down the guideway from and toward the bed, rotating rolls for gripping and lifting the hammer board and head, parts for causing the rolls to move and grip and release the hammer-board, and adjustable parts adapted to be given a rotative movement by the movements of the hammer-head for at the proper time operating the roll-moving parts, as more particularly hereinafter described, and point ed outin the claims.

Of the accompanying illustrations, Figure 1 shows a front elevation of a drop-hammer provided with the invention. Fig.2 shows an enlarged side elevation of the upper portion of the gripping-roll-operating mechanism. Fig. 3 shows a similar view of the lower portion of the same mechanism. Fig. 4 shows a front elevation of the upper portion of the gripping-roll-operating mechanism. Fig. 5 shows a similar view of the lower portion of the same mechanism. Fig. 6 shows a view looking down from the dotted line of Fig. 2. Fig. 7 shows a plan of the hammer-head and the cam represented in Fig. 4 looking down from the dotted line of that figure. Fig. 8 shows a plan of the hammer-head and a view looking down from the dotted line of Fig. 5, and Fig. 9 showsamodified arrangement that may be utilized in place of that shown in Fig.

5'for causing the rolls to grip the hammerboard.

The bed 1 of this drop-hammer may be made of any desirable metal in a-suitable shape to receive and properly support one of the shaping-dies. Extending upwardly from the bed and adjustably mounted thereon'are standards 2, that at their upper ends are joined by a cap-plate 3. The inner edges of the standards are shaped to form a guideway for the hammer-head 4B, which is made of suitably strong and heavy metal and is arranged to receive in its lower face the other of the shaping-dies. The hammer-head has a tai1-board 5, that is usually formed of Wood.

Lifting-rolls 6 are 1nounted,one in front and one behind the hammer-board, upon shafts that are provided with driving-pulleys 7.

The bearings for the rear-roll shaft are preferably permanently fixed in position upon the cap 3, while the bearings for the f rout-roll shaft are formed in the upper ends of the arms of a swinging plate 8, that is pivotally supported bythe cap. The lower end of this swinging plate is connected with. the upper end of a vertical shaft 9, that is loosely supported by brackets 10, secured to one of the standards. Attached to the upper end of the vertical shaft is a block 11, and eccentrically pivoted to this block is a plate 12; One end of a link 13 is hinged to this plate 12, while the other end, which is provided with a globular head, is insertedin a corresponding socket in a socket-piece 14, adjustablymounted in the lower end of the swinging plate. The socket-piece is formed in two parts to permit the introduction into the socket of the head of the link and is threaded an'd screwed into arm 18, which is connected by a hook 19 with an angle-lever 20. A spring 21 is connected between this lever and the standard, and the pull of this spring tends to rock the lever and impart a rotary movement to the shaft, so that the swinging plate connected with the upper end of the shaft will be oscillated and the front roll carried against the face of the hammer-board. When the vertical shaft is free to be given a rotary motion in this man- 'ner, the parts are so moved by the tension of the spring that the hammer-board is gripped between and lifted by the rotation of the two rolls.

Adj ustably secured to the vertical shaft is a spiral cam 22, and projecting from the hammer-head so as to engage with this cam when in its uppermost position is a stud 23. When the hammer-head is lifted, the engagement of this stud with this cam gives a rotary movement to the vertical shaft, and this so moves the connecting parts and oscillates the swinging plate that the front roll is carried away from the hammer-board. This cam is secured to the shaft in such position that at thetime the hammer-head reaches the desired limit of its upward movement the parts are moved sufficiently to release the grip of the rolls from the ham mer-board. If the hammer-head is not then caught by a catch-lever, it will drop to the bed. The amount of upward movement of the hammer-head is determined by the position of the cam 22 on the vertical shaft, and thus by adjusting this cam the force of the drop can be regulated.

A catch-lever24 is pivoted to one of the standards for holding the hammerhead raised. This catch is held by a pivot-pin 34, that can be thrust into any one of a number of sockets 25 that are provided, depending on theheight atwhich it, is desired to hold the hammerhead. The outer end of the catch is adjustably and elastically connected with a rod 26, that is attached to a treadle 27, which is pivotally supported by the bed and normally held lifted, by a spring 28. A spring 29 normally forces the latch into position to engage asocket in a lug 30,. projecting from the hamm,erhead;; but when the treadle isdepressed the catch is'released and the hammer-head free to drop. Just about the moment the dropping hammer strikes a blow upon the piece to be forged awedge 31 on the hammerhead engages and moves an arm 32, that is adiustably secured to a rock-shaft 33 held by brackets attached to one standard adjacent to the lower end, of the vertical shaft 9.

The engagement of thiswedge and arm rocks the shaft 33 and a latch 35, borne by the shaft, so that this latch is disengaged from a locking-rib36 on the vertical shaft 9. When the rib 36 is released, the shaft 9 is free to be giventa rotary movement by the spiral spring 21, and this movement causes the rolls to again grip the hammer-board and as they are rotating lift the hammer for another drop. A spring 37 is arranged to normally hold the rock-shaft 33 so that the latch 35 is in position to engage and hold the rib 36.

If the treadle is held depressed, so that the catch will not engage with and keep the hammer-head raised, the up-and=down move ments of the hammer-head will be continu ous, for at each upward movement by engage= ment with the upper cam the rolls will be moved so as to release the ham mer-board and allow the hammer-head to drop, and at each downward movement by engagement with the rocker-arm the parts will be so moved that the rolls will again grip the hammer-board and lift the hammerhead.

Instead of having a rocker-arm and latch on a rock-shaft at the lower end of the verti cal shaft 9 and a spring for so imparting a r rotary movement to the shaft that the rolls will grip the hammer-board when the blow of the hammer-head is struck, a spiral cam 37, Fig. 9, may be adjustably attached to the lower end of the shaft in position to be engaged by the stud 23, projecting from the hammer-head, This cam may be so arranged instant the blow is struck, the shaft will be given a rotary movement, so that the rolls will grip the hammer-board and again lift the hammer-head. With this form no spring is needed to cause the rolls to grip the hammerboard. The upward movement of the ham mer head by engagement with the upper spiral cam will cause the rolls to release the ham mer-board, and the downward movement of the hammer-head by engagement with the lower spiral cam will cause the rolls to grip the hammer-board. In the first form the upper cam is on the rotative vertical shaft and c is engaged by a stud projecting from thehamimer, while the lower cam is on the hammer and engages a lug on the rock-shaft. In the ashaft the same as the upper, exceptthat it is reversed. The treadle 27 maybe connected by a strap continue the automati-cally-operating appat ratus, and control the movementsof the hammer-head bythe foot of the operative. In this case, however, the latch 35 is held away from the rib 36 by a hook 39;

condition, the depression of the treadle per mits the hammer-head to drop, and the lifting of the foot from the treadle causes the parts to so act that the hammer-head will be raised L and held up.

The mechanisms set forth herein are-very sure in action, for the cams can be regulated i to operate at the exact predetermined times, a and the engagement of the ham mer-head with 7 these cams causes a very positive action for oscillating the vertical shaft and movingthe gripping-roll parts. With these operating mechanisms the powerful effect required for causing the rolls to properly grip the ham merboard is accomplished without any direct blow upon any part, sothat racking the opcrating parts isavoided, wearis eliminated, i and noise is reduced to a minimum. All these parts can be adjusted quickly, so that $31 heavy or light blow can be struck, either that at the proper time, which is about the- 5 second form the lower cam is on the vertical 38- with the lever 20 when it is, desired to dis.

When in this:

singly or continuously, upon work varying in size. The application of the operating mechanism herein disclosed greatly increases the efiriciency and reduces the disagreeable features of drop-hammers.

I claim as my invention 1. In a drop-hammer, in combination with the hammer-head and rolls for raising'the head, a rotative shaft extending substantially parallel with the plane of movement of the head,means connected with the head for imparting a rotary movement to said shaft, and connections between said shaft and the headraising rolls whereby the rolls are caused to alternately raise and release the head, substantially as specified.

2. In a drop-hammer, in combination with the hammer-head and rolls for raising the head, a rotative shaft extending substantially parallel with the plane of movement of the head, means connected with said shaft and projecting into the path of a part of the head whereby said shaft is given a rotary movement in one direction by the upward movement of the head, means connected with said shaft and projecting into the path of a part of the head whereby said shaft is given a rotary movement in a reverse direction by the downward movement of the head, and connections between said shaft and the headraising rolls whereby the rolls are caused to alternately raise and release the head, substantially as specified.

3. In a drop-hammer, in combination with a hammer-head and rolls for raising the head, a rotative shaft extending substantially parallel With the plane of movement of the head, a cam borne by said'shaft, means connected with the head for engaging the cam and imparting to said shaft a rotary movement in one direction,- a spring for imparting to said shaft a rotary movement in the opposite di-' rection, and a connection between said shaft and the head-raising rolls whereby the rolls are caused to alternately raise and release the head, substantially as specified.

4. In a drop-hammer, in combination with the drop-hammer and rolls for raising the head, a rotative shaft extending substantially parallel with the plane of movement of the head, a cam borne by said shaft, means connected with the head for engaging the cam and imparting to said shaft a rotary movement in one direction, a spring for imparting to said shaft a rotary movement in the opposite direction, a latch adapted to engage and retain said shaft against the tension of the spring, a rock-shaft for releasing the latch from the rotative shaft, a part connected with the head for moving the rock-shaft, and connections between the rotative shaft and the head-raising rolls whereby the rolls are caused to alternately raise and release the head, substantially as specified.

FRANCIS A. PRATT.

Witnesses:

HARRY R. WILLIAMS, E. W. FOTHERGILL. 

